Analyzing and understanding molecular interactions is fundamentally important to the life sciences. Exploring these interactions will not only advance the understanding of basic biology, but will provide researchers with the ability design molecules to modify, block, or otherwise affect certain interactions.
There are currently numerous methods available to analyze molecular interactions, including both labeled and label-free mechanisms. Labeling methods include fluorescence, radioactivity, phosphorescence, bioluminescence, and chemiluminescence, among others. Label-free methods include surface plasmon resonance, differential scanning calorimetry, various biosensors such as capacitive, conductometric, and impedimetric sensors, among many other methods. However, these common approaches typically require immobilizing one or both of the interacting molecules on a sensing area such as an assay plate or a sensor surface, thereby constraining their binding activity. When analyzing multivalent bindings, for example, this restriction prevents an accurate measurement of affinity and binding capacity.
Accordingly, there is a continued need in the art for methods and systems that allow for label-free analysis of free-solution molecular interactions with increased resolution.